The latest tag v2.9.3 points to a commit with broken dependencies. Note that lightgbm = { git = "https://github.com/postgresml/lightgbm-rs", branch = "main" } in Cargo.toml still results in the version being pinned in Cargo.lock to commit e20d7b905b28a29d8e8bd2bed84f70835c342eea which seems to be broken and fails to build.